It is well known in the art that the epoxy-group has the ability of reacting with compounds which have an active hydrogen atom, like e.g. with alcohols, phenols, acids, amines or mercapto compounds, according to the following reaction scheme: ##STR1## Therefore, epoxy resins can be crosslinked to yield polymeric products with such crosslinking agents which comprise reactive hydrogen atoms, and nowadays as curing agents for epoxy resins there are used for example the following substances which have active hydrogen atoms:
dicarboxylic acids and polycarboxylic acids, polyalcohols, polyphenols, diamines and polyamines and polymercaptanes. With regard to this, reference is made to Ullmann's "Encyklopadie der technischen Chemie" (Encyclopedia of the technical Chemistry), volume 10, 1975, pages 567-577, and specially to page 570, table 6, in which the different crosslinking reactions are illustrated schematically. PA1 a good workability of the composition, while maintaining an advantageous water/cement value. PA1 the prevention of separation processes, like the settling of components, the segregation or bleading out of components, like aqueous solutions, and the undesired development of a cement layer on the surface. PA1 an increasing of the water retaining ability. PA1 an increased resistance to harmful substances from the environment, like carbonates and salts, like defrosting salts. PA1 an excellent adherence to old surfaces or concrete and other usual undergrounds in the construction field, like on iron, even if the layers to be applied are thin. PA1 U.S. Pat. No. 3,956,208 PA1 DE 2,627,070 PA1 U.S. Pat. No. 4,123,402 PA1 JP 54,148,025 PA1 U.S. Pat. No. 4,179,418 PA1 EP 10,318 PA1 JP 58,023,823 PA1 U.S. Pat. No. 4,489,179 PA1 U.S. Pat. No. 4,539,347 PA1 about 45% (corresponding to about 14 mol-%) of a bis(diamine-diepoxide)-polyethylene glycol-adduct which acts as emulsifying agent, PA1 about 35% (corresponding to about 32 mol-%) of a bis(diamine)-epoxy resin-adduct, PA1 about 20% (corresponding to about 48 mol-%) of bis(acrylonitrile)-diamine-adduct, PA1 a simple method for preparing the curing agent, e.g. according to a one pot process. The temperatures required in the process should not be too high (&lt;100.degree. C.). PA1 the use of any starting materials which are higly toxic, like e.g. acrylonitrile, ethylene-imine and similar products, should be avoided. PA1 the use of organic solvents should be avoided. PA1 the curing agents should be storable even if diluted to a solid content of about 20% at temperatures of up to 50.degree. C. for long periods, without coalescing. PA1 10-80% by weight of at least one emulsifier which comprises in its molecule at least one polyalkylene-polyether-diamine-group which corresponds to formula I ##STR2## in which the radicals R.sup.1 are independently from each other hydrogen atoms or straight chain or branched chain alkyl residues having 1-6 carbon atoms or straight chain or branched chain alkyl radicals having 1-6 carbon atoms which are substituted with one or more phenyl residues, PA1 R.sup.4 are independently from each other alkylene groups having 1-8 carbon atoms, PA1 n is an integer in the range of 1-5, and PA1 x is an integer in the range of 8-90, PA1 y is an integer in the range of 1-6, and PA1 A is an alkylene residue, a cycloalkylene residue, a polyalkylene-polyether-residue or a bivalent residue which comprises alkyl groups as well as cycloalkyl groups and/or aromatic groups. PA1 B is an alkylene residue, an alkylene residue which is interrupted in its alkylene chain through one or more ether oxygen atoms, or a bivalent cycloaliphatic or aromatic or araliphatic residue and PA1 R.sup.1 is selected from the group comprising hydrogen or straight chain or branched alkyl residues having 1-6 carbon atoms and phenyl substituted straight chain or branched alkyl residues which have 1-6 carbon atoms in the alkyl moiety. PA1 B is an alkylene residue or an alkylene residue the carbon chain of which is interrupted through one or more ether oxygen atoms or a bivalent cycloaliphatic or aromatic or araliphatic residue, and PA1 R.sup.1 is selected from the group comprising hydrogen atoms or straight chain or branched alkyl residues comprising 1-6 carbon atoms and phenyl substituted alkyl radicals comprising 1-6 carbon atoms in the alkyl moieties. PA1 B is an alkylene residue or an alkylene residue, the carbon chain of which is interrupted through one or more ether oxygen atoms, or a bivalent cycloaliphatic or aromatic or araliphatic residue, PA1 10-80% by weight of the at least one emulsifier, PA1 1-80% by weight of the at least one coemulsifier, PA1 5-80% by weight of the at least one bis(diamine)-diepoxide-adduct, and PA1 1-80% by weight of the diamine or the mixture of two or more diamines. PA1 B is an alkylene residue or an alkylene residue the carbon chain of which is interrupted through one or more ether oxygen atoms, or a bivalent cycloaliphatic or aromatic group or a bivalent residue which comprises alkyl as well as cycloalkyl and/or aromatic groups. PA1 10-80% by weight of at least one emulsifier which contains in its molecule at least one polyalkylene-polyether-diamine group having the formula I, PA1 1-80% by weight of at least one coemulsifier which comprises in its molecule at least one polyalkylene-polyamine-group having the formula II, and PA1 5-80% by weight of at least one bis(diamine)-diepoxide-adduct which comprises in its molecule at least two epoxid-diamine-adduct groups of formula III, or PA1 R.sup.1, R.sup.4 and the symbols n and x, have the same meaning as defined before, and wherein furthermore the symbol PA1 n is preferably the integer 2 or 3, and PA1 R.sup.5 is a long-chain aliphatic residue, preferably an alkyl residue having 7-25 carbon atoms, or an aliphatic polyamine residue which corresponds to the following formula ##STR13## in which formula R.sup.6 is an alkyl residue having 7-25 carbon atoms, PA1 B is an alkylene residue or an alkylene residue the carbon chain of which is interrupted through one or more ether oxygen atoms or a bivalent cycloaliphatic or aromatic or araliphatic residue, and which process is performed by PA1 R.sup.5 is a long-chain aliphatic residue, preferably an alkyl residue which comprises 7-25 carbon atoms, or an aliphatic polyamine residue which corresponds to the following formula ##STR20## in which R.sup.6 is an alkyl residue having 7-25 carbon atoms, PA1 B is an alkylene residue or an alkylene residue the carbon chain of which is interrupted through one or more ether oxygen atoms, or a bivalent cycloaliphatic or aromatic or araliphatic residue, PA1 B is an alkylene residue or an alkylene residue the carbon chain of which is interrupted through one or more ether oxygen atoms or a bivalent cycloaliphatic or aromatic or araliphatic residue, PA1 1=alkylamine, for example a fatty amine PA1 2=aliphatic diglycidyl ether PA1 3=polyether-diamine, like for instance Jeffamine ED 900, 2001 and further diamines. PA1 4=polyalkylene polyamine, like e.g. triethylene tetramine (TETA), tetraethylene pentamine (TEPA), N,N'-bis-(2-aminopropyl)-ethylene diamine, and so on. PA1 5=cycloaliphatic diamine, like e.g. 3-aminomethyl-3,5,5-trimethyl cyclohexylamine (IPD), m-xylylene diamine (mXDA) and so on. PA1 6=mixtures of aliphatic and aromatic diglycidyl ethers. PA1 an improvement of the gloss of the formed films PA1 a highly improved adherence of the films PA1 a better compatibility of the curing agent with such additives which are usually present in mortar compositions PA1 a better workability of the ECC products which are produced using said curing agents. PA1 Frequently the corresponding products lose their ability of forming microemulsions. It is believed that this is true because the molecules of the emulsifier have in their structure rigid parts which were introduced through the epoxy resin and therefore said molecules obviously are no longer able to bend to such a high extent at the intermediate surfaces between the water phase and the oil phase to form microemulsions. PA1 The problems which are caused through a high viscosity are very severe and sometimes make the product useless. PA1 The films which are formed when said curing agents are used to cure corresponding epoxy resin compositions are unsatisfactroy, because of not good film forming properties due to the inclusion of water. PA1 1=alkylamine, for example a fatty amine PA1 2=bisphenol-A-diglycidyl ether, which is in the future also abbreviated as (BPADGE). PA1 3=polyether-diamine, like for instance Jeffamine ED 900, 2001, and further diamines. PA1 4=diamine, for example 3-aminomethyl-3,5,5,-trimethyl cyclohexylamine (IPD), m-xylidene diamine (mXDA), Jeffamine D-230 and so on. PA1 5=polyalkylene polyamine, like e.g. triethylene tetramine (TETA), tetraethylene pentamine (TEPA) NH-bis-(2-amino propyl)-ethylene diamine, and so on. PA1 6=diamine, for example 2-methyl-penta methylenediamine (MPMD), trimethylhexylmethylenediamine (TMD), Jeffamine D-230, 3-aminomethyl-3,5,5,-trimethyl cyclohexylamine (IPD), m-xylidene diamine (mXDA) and so on.
In spite of the great number of curing agents which are described in the prior art for curing epoxy resins, several of said systems are not suited, if the epoxy resin will be present in a specific form or formulation, for instance as epoxy resin dispersion, respectively the curing agents described in the prior art are not satisfactory when the epoxy resin is intended to be used in a certain field of application.
Said problems are severe if the curing of the epoxy resin has to be performed in a system which contains further components, like e.g. fillers, pigments, emulsifying agents and similar constituents. If the epoxy resin is used in a system which contains inorganic binders, like cement or lime, and eventually further additives, like for instance additives for concrete, then additional difficulties are to be encountered, because of the alkaline properties of said inorganic binders, and because of the further components which usually are present in such compositions. To sum up, until now there was not yet available a curing agent which fulfilled all the set requirements.
On the other hand, it is desired to improve certain technological properties of mortars, specially cement containing mortars, like concrete, by adding certain additives, including polymeric materials, like plastic materials and resins. Through the addition of such further additives, for instance the following properties should be improved, respectively imparted to the composition.
It is well known in the art since many years to add to cement mortars polymeric materials which are thermoplastics. In the following table there are stated the years since when about the corresponding thermoplastic materials had been added to cement mixtures, and in said table furthermore also the disadvantages are mentioned shortly, which said products usually exhibit:
______________________________________ since about thermoplastic material and its the year disadvantages ______________________________________ 1950 polyvinylacetate-polymerizates. They however are quickly saponified under the highly alkaline conditions of the cement suspension. 1958 styrene-butadiene-polymers. They however have only a low stability if submitted to an irradiation with ultraviolet light. 1970 styrene-acrylate-polymers. They have a suf- ficient stability against saponification and also when submitted to an irradiation with ultraviolet light. ______________________________________
Through the addition of dispersions of the above mentioned thermoplastic polymers, it was possible to develop several polymer modified cement mortars which are designated as "Polymer Cement Concrete products" and abbreviated as "PCC-products". The corresponding products have several advantageous properties if compared with corresponding products which were prepared without adding said dispersions of thermoplastic materials. Said products are comfortable in use and not too expensive. Cement mortars, however, very often are submitted to rather severe environmental conditions, like e.g. large variations of temperature, exposures to water, ultraviolet light and different chemical substances and similar influences, and the corresponding products which had been prepared by adding thermoplastic dispersions sometimes have severe disadvantages if submitted to said conditions for longer periods.
Dispersions of thermoplastic material usually contain emulsifiers, protective colloids and/or coalescing agents, and therefore they are susceptible to a microbial attack during the storage period, and frequently even after the curing of the accordingly prepared construction material, provided that said construction material is used in a rather humid environment.
It is well known for a person experienced in the art that through the environment and the influence of weather, construction materials are exposed to drastic variations of the temperature, and also in as far as said temperature changes are concerned, the PCC-products often do not meet the set requirements.
Most of the dispersions of thermoplastic materials are soft at the temperature of use. The glass-transition temperature, which is abbreviated as T.sub.G usually is in the range of +30.degree. C. to -30.degree. C. Often the minimal film forming temperature, which is abbreviated as "MFT" of such thermoplastic materials, is improved by adding coalescing agents which result in a swelling of the thermoplastic material. The corresponding coalescing agents are usually specially selected organic solvents with low volatility, which organic solvents however should evaporate by and by from the corresponding constructions material as soon as the film had been formed. It however was found out that said coalescing agents can no longer evaporate to the desired degree from the formed films of the thermoplastic material if rather thick layers of the construction material had been applied. Even if a polymeric material is used which has a rather high glass-transition temperature, then the corresponding film of the thermoplastic material maintains its softness due to the reasons outlined above.
If the thermoplastic material which is added to the mortar or the concrete is a dispersion which contains an acrylate, then a further disadvantage is to be found in the already mentioned problems of a saponification of the ester groups, through which carboxylic acid groups are formed, if the corresponding mortar or concrete is submitted to water or humidity for long periods, and said carboxylic acid groups make the corresponding thermoplastic polymer more hydrophilic and result in a swelling of the polymer and thereby it gets still more soft.
The above mentioned undesired properties of such mortars to which dispersions of thermoplastic materials had been added, probably are the reason why it was tried already since about the year 1960 to use as additive to mortar or concrete, instead of thermoplastic materials, corresponding dispersions of epoxy resins.